As there is no easy tested solution for this I just created this solution which seems to work. It is basically the same mod as I use in my V6 floppy upgrade kit. But in this case the mod is done internally in the GAL.

This mod could likely be done with the logic level MOSFET in which case it would not need the resistor. But I do not have any these at the time of typing and well.. Life is too short

In any case I use a simple PNP BC558 transistor. Any generic low-power PNP transistor will likely work.

PNP transistor...
connect:

C to 0v (WD pin 14)
B via 1K to MON (pin 20)
E to WP (pin 25)

When MON is high, transistor is off.. When MON is low, transistor turns on, connects WP to 0v. In this case TOS should always assume that disc has changed and should always re-read the FAT.

This program was just a very fast knock up in STOS a few years ago.. But does the job.

If run on a unmodded ST the message will say "Disc has definitely not been changed" constantly.

On a modded ST. After loading and the floppy drive light turns off, the 558 will set WP LO and the message will say "Disc may have changed!". The message shows up regardless of if you actually change the floppy or not.

I have only done some quick tests with this is to work okay obviously others need to try this as well..

I did a quick test to a MPF920 drive as these seem to have a third switch which I use.. Which I assume is media detect switch..

mf9201.jpg (344.31 KiB) Viewed 1306 times

mf9202.jpg (169.77 KiB) Viewed 1306 times

What this does is that when the floppy is ejected, the media switch becomes open circuit and is pulled up to 5 V via a 1K resistor on the motherboard. This then turns on the BC548 NPN transistor which connects WP to 0V.

So with this modification TOS only informed of a disc change when the disc is physically ejected..

This mimics the behaviour of the Epson 480 drive which I tested. However the Epson drive only pulses WP low, My fix keeps WP low all the time until the disc is inserted. I do not really see there being any difference to either method... But obviously this mod should be tried by others also..

I am also actually assuming this switch which I am calling media detect switch, is actually media detect switch.. There could be other switches use with 2.88MB floppies, but in the case of this drive it doesn't seem to be near any holes for any floppy types..

OK, I will do this one first then. I think this is in effect what the Alison wire was doing.. the positions look the same. But I also have an NPN transistor I can use, so I will do your mod and confirm.

OK, I will do this one first then. I think this is in effect what the Alison wire was doing.. the positions look the same. But I also have an NPN transistor I can use, so I will do your mod and confirm.

I don't know what Alison was doing, but this mod cannot be done to simple wire.. Transistor is being used as a inverter... As when there is no floppy inserted, which contacts break, and once which pin is pulled to 5 V.. We need to switch WP to 0V.. So obviously we need inversion here... And the transistor also acts as tri-state buffer.. In that when the switch is closed, the transistor is turned off and does not affect the WP signal.